From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 24614C2D0DA for ; Sun, 29 Dec 2019 18:40:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 08739206DB for ; Sun, 29 Dec 2019 18:40:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727158AbfL2SkM (ORCPT ); Sun, 29 Dec 2019 13:40:12 -0500 Received: from mx1.yrkesakademin.fi ([85.134.45.194]:16164 "EHLO mx1.yrkesakademin.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726455AbfL2SkL (ORCPT ); Sun, 29 Dec 2019 13:40:11 -0500 Subject: Re: [PATCH 5.4 252/434] perf probe: Fix to probe a function which has no entry pc To: Greg Kroah-Hartman , CC: , Arnaldo Carvalho de Melo , Arnaldo Carvalho de Melo , Masami Hiramatsu , Jiri Olsa , Namhyung Kim , Sasha Levin References: <20191229172702.393141737@linuxfoundation.org> <20191229172718.657510315@linuxfoundation.org> From: Thomas Backlund Message-ID: Date: Sun, 29 Dec 2019 20:40:09 +0200 MIME-Version: 1.0 In-Reply-To: <20191229172718.657510315@linuxfoundation.org> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-WatchGuard-Spam-ID: str=0001.0A0C0201.5E08F30B.0009,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0 X-WatchGuard-Spam-Score: 0, clean; 0, virus threat unknown X-WatchGuard-Mail-Client-IP: 85.134.45.194 X-WatchGuard-Mail-From: tmb@mageia.org Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Den 29-12-2019 kl. 19:25, skrev Greg Kroah-Hartman: > From: Masami Hiramatsu > > [ Upstream commit 5d16dbcc311d91267ddb45c6da4f187be320ecee ] > > Fix 'perf probe' to probe a function which has no entry pc or low pc but > only has ranges attribute. > > probe_point_search_cb() uses dwarf_entrypc() to get the probe address, > but that doesn't work for the function DIE which has only ranges > attribute. Use die_entrypc() instead. > > Without this fix: > > # perf probe -k ../build-x86_64/vmlinux -D clear_tasks_mm_cpumask:0 > Probe point 'clear_tasks_mm_cpumask' not found. > Error: Failed to add events. > > With this: > > # perf probe -k ../build-x86_64/vmlinux -D clear_tasks_mm_cpumask:0 > p:probe/clear_tasks_mm_cpumask clear_tasks_mm_cpumask+0 > > Committer testing: > > Before: > > [root@quaco ~]# perf probe clear_tasks_mm_cpumask:0 > Probe point 'clear_tasks_mm_cpumask' not found. > Error: Failed to add events. > [root@quaco ~]# > > After: > > [root@quaco ~]# perf probe clear_tasks_mm_cpumask:0 > Added new event: > probe:clear_tasks_mm_cpumask (on clear_tasks_mm_cpumask) > > You can now use it in all perf tools, such as: > > perf record -e probe:clear_tasks_mm_cpumask -aR sleep 1 > > [root@quaco ~]# > > Using it with 'perf trace': > > [root@quaco ~]# perf trace -e probe:clear_tasks_mm_cpumask > > Doesn't seem to be used in x86_64: > > $ find . -name "*.c" | xargs grep clear_tasks_mm_cpumask > ./kernel/cpu.c: * clear_tasks_mm_cpumask - Safely clear tasks' mm_cpumask for a CPU > ./kernel/cpu.c:void clear_tasks_mm_cpumask(int cpu) > ./arch/xtensa/kernel/smp.c: clear_tasks_mm_cpumask(cpu); > ./arch/csky/kernel/smp.c: clear_tasks_mm_cpumask(cpu); > ./arch/sh/kernel/smp.c: clear_tasks_mm_cpumask(cpu); > ./arch/arm/kernel/smp.c: clear_tasks_mm_cpumask(cpu); > ./arch/powerpc/mm/nohash/mmu_context.c: clear_tasks_mm_cpumask(cpu); > $ find . -name "*.h" | xargs grep clear_tasks_mm_cpumask > ./include/linux/cpu.h:void clear_tasks_mm_cpumask(int cpu); > $ find . -name "*.S" | xargs grep clear_tasks_mm_cpumask > $ > > Fixes: e1ecbbc3fa83 ("perf probe: Fix to handle optimized not-inlined functions") > Reported-by: Arnaldo Carvalho de Melo > Tested-by: Arnaldo Carvalho de Melo > Signed-off-by: Masami Hiramatsu > Cc: Jiri Olsa > Cc: Namhyung Kim > Link: http://lore.kernel.org/lkml/157199319438.8075.4695576954550638618.stgit@devnote2 > Signed-off-by: Arnaldo Carvalho de Melo > Signed-off-by: Sasha Levin > --- > tools/perf/util/probe-finder.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c > index 7857ae7a10b7..4079ed617f53 100644 > --- a/tools/perf/util/probe-finder.c > +++ b/tools/perf/util/probe-finder.c > @@ -994,7 +994,7 @@ static int probe_point_search_cb(Dwarf_Die *sp_die, void *data) > param->retval = find_probe_point_by_line(pf); > } else if (die_is_func_instance(sp_die)) { > /* Instances always have the entry address */ > - dwarf_entrypc(sp_die, &pf->addr); > + die_entrypc(sp_die, &pf->addr); > /* But in some case the entry address is 0 */ > if (pf->addr == 0) { > pr_debug("%s has no entry PC. Skipped\n", > Still broken... /usr/bin/ld: perf-in.o: in function `probe_point_search_cb': /work/rpmbuild/BUILD/kernel-x86_64/linux-5.4/tools/perf/util/probe-finder.c:1012: undefined reference to `die_entrypc' -- Thomas